At least 20 people were killed and dozens more injured as fresh unrest erupted in Indonesia’s restive Papua region Monday, with some victims burned to death in buildings set ablaze by protesters, authorities said.

“Most of them died in a fire,” said Papua military spokesman Eko Daryanto. “The death toll could go up because many were trapped in burning kiosks.”

Hundreds of protesters in Indonesia’s restive Papua province have set fire to homes and other buildings.

Papua police chief Rudolf Alberth Rodja said Monday’s demonstration was sparked by rumors that a high school teacher in Papua’s Wamena city called students “monkeys.”

He says the angry mob set fire to local government buildings, shops, homes, and motorbikes.

Television footage showed black smoke billowing from the burning buildings.

Rodja says a police investigation did not find any racist comments made about the students.

Monday’s protest came days after Indonesian authorities managed to get the province under control after weeks of violent protests against racism in the region, where an insurgency has simmered for decades.